19991938 has 8 divisors (see below), whose sum is σ = 30139200. Its totient is φ = 9945540.

The previous prime is 19991911. The next prime is 19991963. The reversal of 19991938 is 83919991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 19991891 and 19991900.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24718 + ... + 25513.

It is an arithmetic number, because the mean of its divisors is an integer number (3767400).

Almost surely, 2^19991938 is an apocalyptic number.

19991938 is a deficient number, since it is larger than the sum of its proper divisors (10147262).

19991938 is a wasteful number, since it uses less digits than its factorization.

19991938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50432.

The product of its digits is 157464, while the sum is 49.

The square root of 19991938 is about 4471.2345051451. The cubic root of 19991938 is about 271.4052840330.

The spelling of 19991938 in words is "nineteen million, nine hundred ninety-one thousand, nine hundred thirty-eight".